If the Defiant is, as Sisko said, nothing more or less than a warship, then why does it keep getting scientific research missions? It was used for generating a wormhole in "Rejoined", and for investigating the anomaly in this episode. Surely a dedicated science vessel would be far better equipped?

When O'Brien has to leave the ship, he quite correctly says he will have trouble breathing because his body can't absorb the very large (to him) Oxygen molecules. Great, excellent bit of clear scientific thinking by the writers! Of course... he could just put on an environmental suit from the Runabout, which would have an Oxygen supply with molecules that had shrunk just as much as he had.

Great Moment :

Seeing the little Runabout zipping around in side the Defiant. Seriously cool!

Factoid :

Fritz Sperberg also played Ranek in Voyager's "Body and Soul".

Plotline

A peculiar spatial anomaly reduces a Runabout and its occupants to just a few inches long. But after the Defiant is captured by the Jem'Hadar, their only hope rests with one little ship.